This artist's concept shows how NASA's Voyager 1 spacecraft is bathed in solar wind from the southern hemisphere flowing northward. (NASA/JPL-Caltech)
The Voyager 1 spacecraft is traveling through a previously unknown region of deep space as it heads out of our solar system, which might happen soon, scientists reported Monday.
Voyage and its twin, Voyager 2, were launched in 1977 and will become the first man-made objects to exit our celestial neighborhood -- relatively soon.
"We don't know exactly how long it will take," Edward Stone, a project scientist, told reporters during a teleconference, Space.com reports. "It may take two months, it may take two years."
"We do believe this may be the very last layer between us and interstellar space," he said. "This region was not anticipated, was not predicted."
Both spacecraft, which continue to send data back to Earth, are in the heliosheath, the outermost layer of the heliosphere. That's where the force of interstellar cosmic ray particles slows the solar wind generated by the sun.
Scientists, meeting Monday in San Francisco, dubbed the new region a "magnetic highway," where charged particles from inside and outside the heliosphere flow out and in. NASA posted animations imagining what the Voyagers are experiencing, if the naked-to-the-eye ions could be seen.
The twin probes explored Jupiter, Saturn, Neptune and Uranus between 1979 and 1989.